Matching Intercooler to Turbo Size

[Berger]

Hows it best done, matching the size of the intercooler to the size/boost pressure your running on your turbo.

Obviously you want the air to be kept cool, but theres going to be an ideal size for response while keeping temperatures down. If you go too big you will increase lag, but too small and the temperatures will rocket.

How can you calculate whats best or is it just trial and error?

 

[Meridian]

Surely no intercooler has enough volume to cause any appreciable lag? I've never even heard of it being an issue.


M

 

[Berger]

I was under the impression that masses of piping and huge intercoolers could give more lag/less throttle response.

It seemed a bit odd in my head as i expected the turbo to flow the air that quickly through the system that it wouldnt make a bean of difference, but ive no mechanical/engineering background so i could be way wrong.

Either way, whats the best method of doing it, ive got an intercooler here which has a large area, but is fairly slim, and a smaller one thats pretty deep.

To me the thinner one would be more efficient as its got a much larger area to dissipate the heat, however this wont take into account the airflow over the IC.

 

[Firestar_3x]

I was under the impression a bigger intercooler can cause issues with turbo Lag & throttle response, this is compounded if you purchase as cheap intercooler you can also see a nasty pressure drop.

 

[Berger]

Ive got a larger area intercooler to the standard one which i bought with a load of other parts, so im swapping the turbo and the intercooler on my car.

The new intercoolers similar size to the radiator, maybe 500mm (length) by 300mm (height) but only perhaps 30mm thick, sits infront of the radiator getting loads of cool air.

The old ones maybe 200 by 100 but about 60 thick. This was good enough to run 12psi with the standard T25 turbo, sits above the radiator getting some air but not as good as it could be.

Ill be looking to run 12 or 13 psi with the larger T28 turbo. Now it should run a little cooler as the turbo wont be working as hard as i see it, but i wasnt sure if the intercooler would be up to the task.

Most people run an intercooler thats about 500 by 100 by 60 thick, wondering if ill be OK as its roughly double the height but only half the thickness.

Could insert a temperature probe into the boost hose, as long as it doesnt come loose it should be OK. What sort of temperatures are generally *good* for the hose between the IC and TB.

 

[Meridian]

I was under the impression that masses of piping and huge intercoolers could give more lag/less throttle response.

The piping, yes; the i/c itself, no. A full front-mount on a (say) scoob has about eight feet or more of piping. Unless you have only a couple of feet of piping then the difference in volume of the larger i/c is just too small in comparison.


M

 

[Jonnycoupe]

Half the lag issue is from the higher resistance in the charge pipework/system, the turbo has to achieve a higher pre cooler pressure than the boost in the inlet manifold. This takes more time.